Undesirable, uncultivated plants--often characterized simply as "weeds"--are able to reduce yields of cultivated plants and other useful agricultural crops by competing with cultivated plants. As a result, weeds interfere with the growth of seeds, vegetables, fruits, and foliage.
Weeds are able to cause this sort of undesirable result because of the tendency of weeds to compete aggressively with cultivated plants for available light and space, moisture, and nutrients in the soil.
Furthermore, and as is well-known to those skilled in the crop-protection art, various commercially-important food plants as well as plants that are used for structural and ornamental purposes are yet additionally vulnerable to the devastation caused by insect pests.
Such sorts of pests represent a particularly serious economic threat, especially to such important cereals as rice and corn.
For this reason, there is an ongoing need for the development of crop-protection compositions that are ever more effective both against weeds and such pests as insects, mites, nematodes, and so forth.
There is, moreover, a particularly wide-spread desire throughout the industry for the development of crop-protection compositions that are not only environmentally-friendly but also satisfactorily effective at relatively low concentrations. It would thus be highly desirable for such compounds to advantageously possess activity to control weeds and other pests without causing attendant environmental difficulties.
U.S. Pat. Nos. 4,746,352 and 4,760,163--both to Wenger et al.--disclose uracil esters and their salts, which are reported to possess herbicidal properties.
In U.S. Pat. No. 4,280,999 to Steelman et al., moreover, an "insecticidal" method that utilizes uracils is discussed.
Disclosed and detailedly reported in U.S. Pat. No. 5,134,144 to Walter Brouwer, Ethel Felauer, Paul McDonald et al. (three of the present inventors) are certain uracils--ether uracils and thioether uracils--that were surprisingly discovered to possess miticidal, insecticidal, and nematocidal activities at relatively low concentrations.
Separately, in U.S. Pat. No. 5,134,145 to Brouwer, Felauer and McDonald (three of us) there are disclosed and detailedly reported certain other uracils--ester uracils--which we surprisingly discovered similarly possess miticidal, insecticidal, and nematocidal activities, also at relatively low concentrations.